pub fn new_birthday_probability(n: u32) -> f64 {
    // TODO: 这里写逻辑
    let mut p_a = 1.0;
    for i in 0..n {
        p_a *= (365-i) as f64;
        p_a /= 365 as f64;
    }
    // 1.0 - p_a
    ((1.0 - p_a) * 10000.0).round() / 10000.0 
}
